1. Field of the Invention
The present invention relates to a liquid crystal display(LCD) and a manufacturing method thereof, and more particularly to an improved liquid crystal display and a manufacturing method thereof capable of advantageously reducing point defects caused due to the defects of the thin film transistor and of increasing an aperture ratio by providing an upper and lower structures of a pixel electrode.
2. Description of the Conventional Art
Conventionally, a thin film transistor used in a conventional LCD is shown in FIGS. 1A to 1D. As shown therein, a gate electrode 2 is formed on a predetermined portion of a substrate 1. Here, the gate electrode 2 is formed by selectively etching a metal layer using a photomask. In addition, on the upper portion of the gate electrode 2 is deposited an insulating material for forming an insulating film 3, on which an amorphous silicon film 4 is deposited. Thereafter, as shown in FIG. 1B, on the amorphous silicon film 4 is deposited a dopant amorphous silicon film 5, in which impurity objects, i.e., Phosphor, are doped. In addition, the dopant amorphous silicon film 5 and the amorphous silicon film 4 are etched using the same mask. Thereafter, as shown in FIG. 1C, on a predetermined portion of the insulating film 3 is formed a first transparent conductive film 6 which is used as a pixel electrode. Thereafter, as shown in FIG. 1D, on the first transparent conductive film 6 is deposited a metal film and then the metal film is selectively etched, whereby source/drain electrodes 7 are formed thereon.
However, the conventional thin film transistor, as shown in FIG. 2, have drawbacks in switching operation when the wirings respectively to either the gate electrode 2 or the source/drain electrode 7 become cut.
Accordingly, in an attempt to resolve such problems, one method of using a plurality of transistors, as shown in FIG. 3, is developed. In this case, if at least one transistor has a defect, another transistor normally works, so that at least somewhat the defect might be compensated. However, in the above case, the aperture ratio of the display cannot be improved.